Improvement in hot-blast ovens



UNITED STATESv PATENT OFFICE.

RICHARD LONG, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN HOT-BLAST OVENS.

Speciication forming part of Letters Patent No. 125,138, dated April 2, 187g; untedated March 16, 1872.

Specification describing certain Improvements in Hot-Blast Ovens, invented by RICH- ARD LONG, of Pittsburg, in the county of Allegheny and State of Pennsylvania.

Figure l is a horizontal section, and Fig. 2 is a side elevation with the casing-wall vre"- moved.

This invention relates to an oven for heating the blast of a furnace by means ofthe combustion within the oven of gases drawn from the furnace, the chief novelty of the invention consisting of an apparatus for burning the gases inside offlues,made ofre-clay blocks orbricks, passing vertically through the oven, while the air or blast is passed through chambers formed from the spaces left between said flues, the air, therefore, passing outside of the tlues or pipes instead ot' through or inside of them, the latter having been, up to the date of my invention, the common niode of conducting the air for being heated.

Referring to the drawing, a a are the vertical gas-tlues, the same resting on tile plates b, and supporting at their tops other tile plates c.

Plates d, made either of lire-clay tile, wrought or cast iron, rest on top of the lues a, which plates are provided with chimneys f, and, being removable, enable the lu'es to be opened at any time forthe purpose of cleansing. These ues are made of pressed fire-clay blocks or bricks, put together in such a manner that all cracking and leakage are prevented, and are intended as a substitute for fire-clay pipes, which, being made all in one piece, are far moreliable to crack and leak. These dues, constructed in the manner above mentioned, are capable of withstanding any amount of heat without opening or cracking, and I therefore consider them a great improvement over reclay pipes. Between the lues ct are placed walls g, which divide the spaces between the lues, forming thereby chambers It, one between each set, of four (or more) contiguous hues. An aperturethrough thetop of the arches of the combustion-chamber and through the tile plate b is formed for the admission of the burning gases from the lower combustionchambers into the fines above, where the combustion of the gases is completed, and from which the lines are heated. The air or blast passes through the chambers h outside of the lgas-hues, deriving its heat therefrom.

Heretofore it has been customary to pass the air through or inside of the heating-pipes. By burning the gases inside of the lines or pipes and passing the air outside ofthe same I'iind that the pipes are far less liable to crack or burst by reason of the pressure of the blast being exerted on them from without inward, iu which direction they are necessarily more capable of withstanding pressure, and also that I gain a heating-surface increased by as much as the areas of the exteriors of the hues ct exceed the areas of their interiors. My method is, therefore, an improvement on the former one.

Openings t are left in the dividingwalls g to enable the blast to pass from one chamber to another, the blast passing through one of these chambers at a time, these openings serving as elbows or bed-pipes, which have heretofore been used to convey the air. from one pipe or section of pipes to another, thus avoiding the use of either elbows or bed-pipes with their joints and great danger of leakage. Iron stay-rods j run lengthwise through the walls g and through the top and bottom plates b c, lockin g the entire structure together very hrmly, and being themselves protected from the heat of the blast by the walls which inclose them, and when completed the entire oven is rmly locked together by heavy bars of angleiron running across the top, and iron stay-rods running from these bars down the outside of the casing-walls are secured by nuts to the cast-iron base or foundation-plate on which these walls rest.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. llhe gas-hues a, made of pressed ireclay blocks or bricks, as herein speciiied.

2. The combination of the flues a with the upper and lower tile plates b c, as described.

3. The combina-tion of thev fines a with the 7. The chambers 7L, when formed between removable top plates d and chimney j', as set the il ues a, whether with or Without the walls forth, sind for the purposes herein described, g, for the purpose of conducting the air out- 4. rlhe combination of the `cile plates b c, side of said lines, as herein set forth.

Walls g, and stay-rods 7', :1s explained. RICHARD LONG.

5. The walls g, combined with the ues a,

as described. Attest:

6. The walls g, provided. with the openings JNO. A. WILSON,

fr', as described. DANL. W. OLEGAR. 

